Digital microfluidics deals with the manipulation of discrete liquid droplets on a surface. Further, digital microfluidics can be contrasted with microchannel microfluidics, in which liquid droplets are disposed and manipulated within a microchannel. Digital microfluidic droplet manipulation technologies can include the use of surface acoustic waves, thermocapillary forces, electrowetting, dielectrophoresis, optical forces, or magnetic forces. However, the effectiveness of some previous digital microfluidic devices has been limited. Some electrowetting devices, for example, fixed electrode configurations, and/or fixed droplet volumes. Some optoelectrowetting devices require high threshold voltages and also the use of high power optical illumination. In addition, some devices suffer from low droplet manipulation speeds and/or the inability to move a droplet in a desired direction on a device surface.
Therefore, there exists a need for improved microfluidic devices that can provide superior performance and/or efficiency.